This invention pertains generally to treating and dispensing of water and more particularly to a method and apparatus for producing and dispensing highly purified water.
Prior art techniques for making highly purified water (e.g. 10 parts per million total dissolved solids) from potable water (e.g. up to 1000 parts per million total dissolved solids) such as that supplied by a municipal water supply or reservoir have included filtration, carbon adsorption, deionization, distillation and reverse osmosis followed by either deionization or distillation. When reverse osmosis is combined with either deionization or distillation, a storage tank is required between the reverse osmosis unit and the other stage due to limitations on pressure and flow rates in ion exchange and distillation.
Heretofore, there have been attempts to dispense purified or demineralized water through vending machines located at supermarkets and in other areas accessible to the public. Such machines have required frequent maintenence, and leakage and spillage have made them unsuitable for use in some locations, for example, inside supermarkets or where water spillage would produce a hazardous slippery condition on the floor or ground around the machine. Moreover, the size of such machine is generally limited by space considerations and the capacity of the machine to dispense water would be severely reduced by the space occupied by the tank between purification stages.